Equipment and systems that are exposed to the elements often degrade over time due to the effects of corrosion. Corrosive effects are normally cumulative and assume phenomenal proportions over a period of time leading to equipment and system failures. Common equipment that is subject to corrosive effects include aircraft and water craft since they operate under conditions such as extreme temperature, extreme pressure, and high levels of moisture.
To study, gauge, and predict the effects of corrosion, advanced imaging technologies have been used to capture data that depict the corrosion. Some of these technologies include the Time-Of-Flight Diffraction (TOFD) technique, Electromagnetic Acoustic Transducers (EMAT), Ultrasonic technology, Eddy-Currents, and digital radiography imaging.
One type of corrosion common among equipment is pitting. FIG. 1 illustrates in diagrammatic form some of the many forms of pitting corrosion. The pitting corrosion illustrated in FIG. 1 includes subsurface pits, undercutting pits, vertical grain attack, horizontal grain attack, deep narrow pits, elliptical pits, shallow pits, and a mesa attack. Pitting corrosion may be very complex due to the process of corrosion growth and the type of pit formation as illustrated in FIG. 1. If left unchecked, such pitting will enlarge and eventually lead to failure of the equipment.